Investigations into and efforts to develop plastics within the field of the invention have been extensive.
For example, the inventor herein named has developed resin blends for making plastic articles that are hydrodegradable, i.e., water dispersible, based on the use of polyethyleneoxide ("PEO") in combination with certain functionally compatible polymers. The inventor has also developed biodegradable resin blends based on the use of polycaprolactone ("PCL") in combination with functionally compatible polymers. Investigations continue for additional plastic resins that will process in conventional manners and cycle times and that will produce products that are biodegradable and compostable in municipal waste.
The compostability of plastics and other materials is determined by judging the same in comparison with microcrystalline cellulose under controlled composting conditions in accordance with ASTM Standard D. 5338-92. It is widely known that nature handles cellulose well. Consequently, and because the standard of comparison is microcrystalline cellulose, investigations have been conducted in respect of various cellulose compounds, e.g., hydroxypropylcellulose.
One group of cellulose compounds that has not been seriously investigated is the group of compounds and resin blends comprised in major part of cellulose acetate, presumably because cellulose acetate is generally known to be essentially nondegradable.